3,046 research outputs found
Detecting Search and Rescue Targets in Moving Aerial Images Using Eye-Gaze
Eye gaze performance is measured and characterised in the context of moving image inspection. The application domain is that of Wilderness Search and Rescue. Here, moving terrain images captured by an Unmanned Aerial Vehicle (UAV) must be inspected accurately and with minimal delay to attempt identification of a missing person or related artefacts. An exploratory pilot experiment using images of real terrain established the extent of gaze for North and East movement of the UAV at four different speeds, and also for the condition in which a sequence of static frames of the same moving image was inspected. Observation were also made of the gaze tracking behaviour initiated by a potential target. Suggestions are made about the way in which the observation and characterization of eye gaze may be harnessed to enhance the success of target detection in a search and rescue context.Accepted versio
Properties and characterization of ALD grown dielectric oxides for MIS structures
We report on an extensive structural and electrical characterization of
under-gate dielectric oxide insulators Al2O3 and HfO2 grown by Atomic Layer
Deposition (ALD). We elaborate the ALD growth window for these oxides, finding
that the 40-100 nm thick layers of both oxides exhibit fine surface flatness
and required amorphous structure. These layers constitute a base for further
metallic gate evaporation to complete the Metal-Insulator-Semiconductor
structure. Our best devices survive energizing up to ~3 MV/cm at 77 K with the
leakage current staying below the state-of-the-art level of 1 nA. At these
conditions the displaced charge corresponds to a change of the sheet carrier
density of 3 \times 1013 cm-2, what promises an effective modulation of the
micromagnetic properties in diluted ferromagnetic semiconductors.Comment: 8 pages, 5 figures, 14 reference
Current challenges in de novo plant genome sequencing and assembly
ABSTRACT: Genome sequencing is now affordable, but assembling plant genomes de novo remains challenging. We assess the state of the art of assembly and review the best practices for the community
Analysis and calibration of absorptive images of Bose-Einstein condensate at non-zero temperatures
We describe the method allowing quantitative interpretation of absorptive
images of mixtures of BEC and thermal atoms which reduces possible systematic
errors associated with evaluation of the contribution of each fraction. By
using known temperature dependence of the BEC fraction, the analysis allows
precise calibration of the fitting results. The developed method is verified in
two different measurements and compares well with theoretical calculations and
with measurements performed by another group.Comment: 17 pages, 8 figure
Two unusual silicoflagellate double skeletons
A study of silicoflagellate double skeletons revealed two unusual doublets that are illustrated and discussed here. One of these comprises two ten-sided Octactis skeletons that appear to form a doublet, but both in the same (apical) orientation. The other specimen is a double skeleton of Dictyocha
that is slightly disarticulated, with a third, less robust skeleton in between. These unusual double skeletons suggest that there is much more to be learned about the formation of silicoflagellate skeletons and the reproductive processes in this protist grou
A decision-making framework for restoring riparian zones degraded by invasive alien plants in South Africa
Riparian habitats in many parts of South Africa are severely degraded by invasive alien plants, especially trees. These invasions reduce water yields from catchments and affect riverine functioning and biodiversity. Initiatives are under way countrywide to clear alien plants from watercourses and surrounding catchments. Current understanding of key processes that regulate riparian functioning and define options for restoration is rudimentary. We review the impacts of riparian invasions and identify factors limiting the recovery of natural vegetation following alien clearance. We propose a framework of strategic interventions for optimizing restoration success. The framework identifies abiotic and biotic barriers to restoration at the scales of catchments and local reaches. In highly transformed catchments, interventions at the reach scale may fail if important barriers at the catchment scale are not addressed. The extent to which propagule supply and microsite conditions inhibit vegetation recovery is unknown. We also know little of the relative importance of dispersing vegetative propagules, dispersing seeds and soil-stored seed banks in vegetation dynamics, particularly after severe disturbances such as dense invasion by alien plants. The importance of geomorphological and hydrological factors in mediating recovery of riparian vegetation has not been adequately explored for all climatic areas in South Africa. More research is needed to determine the influence of different alien species and clearing treatments on the recovery of riparian vegetation. The literature strongly suggests that in highly alien-transformed catchments, the re-introduction of riparian species is required to promote recovery and suppress re-invasion. However, such interventions are unlikely to be widely implemented unless the cost: benefit ratios are favourable
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